The invention discloses a kit for detecting mutation of a sensorineural deafness pathogenic gene GJB2. The kit comprises a reagent for extracting DNA from a sample to be detected, a PCR reaction reagent for amplifying the DNA of the sample, and a reagent for sequencing a PCR amplification product; wherein the PCR reaction reagent for amplifying the DNA of the sample comprises a PCR primer. The kitis used for detecting whether a GJB2 gene c. 142C) T mutation exists in a patient so as to diagnose the cause of sensorineural deafness; the kit facilitates clinically developing GJB2 mutation screening work of sensorineural deafness patients, and provides a basis for the diagnosis of sensorineural deafness.